Terms
Last updated 25 June 2026 · Crux v0.2 preview
Crux is a free, in-preview math-coaching prototype. It is provided as-is, without any warranty. We're learning from your usage to improve the product before it goes commercial.
What Crux is
An adaptive practice system covering ~27 math curricula. The content is AI-generated and AI-validated. We do our best to make it accurate, but it is NOT a substitute for your school curriculum, a registered teacher, or official preparation materials. Always cross-check against your authoritative syllabus.
What you agree to
- Use Crux for personal learning. Don't try to scrape it, abuse the rate limits, or reverse-engineer it for a competing product.
- Don't input personal information about yourself or anyone else. Crux doesn't need it.
- If you find an item that is wrong or misleading, please report it via email (sushmita@yuriskin.com). This is the most valuable feedback we can receive right now.
What we promise
- To use your activity data only to make the product better — never to sell it, never to send you marketing emails (we don't have your email anyway).
- To honour deletion requests within 30 days.
- To be honest about what the product can and can't do. The mastery estimates and predicted scores are best-effort estimates, not promises.
Limitation
Because this is a free preview, we provide no warranty about the accuracy of any specific item, the calibration of any score estimate, or the availability of the service. If Crux makes a mistake, that's on us to fix — please tell us.
Changes
We'll update these terms as the product matures. We'll note the date of any material change at the top of this page.